Question

3 sin square 20 - 2tan square 45 + 3 sin square 70​

Answer 1

3sin^2 20°+3sin^2 70°–2tan^2 45°

3sin^2 20°+3cos^2 (90–70)°–2tan^2 45°

3sin^2 20°+3cos^2 20°–2tan^2 45°

3(sin^2 20° + cos^2 20°) – 2×(1)^2

3×1 –2

1